Role of interface potential barrier, Auger recombination and temporal coherence in In0.5Ga0.5As/GaAs quantum dots based p-i-n light emitting diodes

Singh, Mohit Kumar; Bhunia, Amit; Al Huwayz, Maryam; Gobato, Y Galv�o; Henini, Mohamed; Datta, Shouvik

Abstract

© 2018 IOP Publishing Ltd. In this work, we investigate the mechanisms that control the electroluminescence from p-i-n heterostructures containing self-assembled In 0.5 Ga 0.5 As quantum dots embedded inside a GaAs/Al 0.3 Ga 0.7 As quantum well as a function of temperature and applied bias. Our results reveal that the carrier dynamics at the interface between the quantum dot and the quantum well play a crucial role in the electroluminescence emission. At low temperatures, two distinct emission bands are observed. Initially at low bias current, we observe broad emissions from the quantum wells and wetting layers. Another dominant and sharp emission at lower energy arises from the quantum dots, but only at higher bias currents. We discuss how a potential barrier between the quantum dots and quantum well can control the density of injected carriers undergoing optical recombination. We have also investigated the role of carrier capture and escape, quantum-confined stark effect and band-filling effects in the electroluminescence emission. In addition, we demonstrate how measurements of temporal coherence of individual spectral peaks, can detect the presence of Auger recombination in quantum dots under high injection currents. Interestingly, a significant increase in the temporal coherence of quantum dot emissions is observed, which could be due to a decrease in Auger recombination with increasing temperature.

Citation

Singh, M. K., Bhunia, A., Al Huwayz, M., Gobato, Y. G., Henini, M., & Datta, S. (2019). Role of interface potential barrier, Auger recombination and temporal coherence in In0.5Ga0.5As/GaAs quantum dots based p-i-n light emitting diodes. Journal of Physics D: Applied Physics, 52(9), Article 095102. https://doi.org/10.1088/1361-6463/aaf61c

• Journal Article Type: Article
• Acceptance Date: Dec 4, 2018
• Online Publication Date: Dec 28, 2018
• Publication Date: Feb 27, 2019
• Deposit Date: Dec 10, 2018
• Publicly Available Date: Dec 29, 2019
• Journal: Journal of Physics D: Applied Physics
• Print ISSN: 0022-3727
• Electronic ISSN: 1361-6463
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 52
• Issue: 9
• Article Number: 095102
• DOI: https://doi.org/10.1088/1361-6463/aaf61c
• Public URL: https://nottingham-repository.worktribe.com/output/1395111
• Publisher URL: https://iopscience.iop.org/article/10.1088/1361-6463/aaf61c
• Additional Information: Journal title: Journal of Physics D: Applied Physics; Article type: paper; Article title: Role of interface potential barrier, Auger recombination and temporal coherence in In0.5Ga0.5As/GaAs quantum dot-based p-i-n light emitting diodes; Copyright information: © 2018 IOP Publishing Ltd; Date received: 2018-09-26; Date accepted: 2018-12-04; Online publication date: 2018-12-28